The present invention relates to a manufacturing method of a semiconductor substrate such as a semiconductor wafer, a TFT (Thin Film Transistor) liquid crystal substrate, a thin film multi-layer substrate and a printed board, which have respectively micro fine circuit patterns or wiring patterns, at a high yield rate, a method and apparatus for measuring highly precise dimensions of patterns to be inspected, which comprises micro fine circuit patterns or wiring patterns formed on the object to be inspected such as the semiconductor wafer, the TFT liquid crystal substrate, the thin film multi-layer substrate and the printed board and inspecting the patterns on the object to be inspected, a method and apparatus for detecting micro fine defects of the patterns on the object to be inspected, and a microscope to be used in the aforementioned detection method.
Recently, the patterns to be inspected, each comprising circuit patterns or wiring patterns formed on, for example, the semiconductor wafer, the TFT liquid crystal substrate, the thin film multi-layer substrate and the printed board have been adapted to be further micro-structured in response to the needs for high density integration. Since the circuit patterns or the wiring patterns are further micro-structured along with high density integration, a defect which should be detected becomes smaller or finer. Detection of such micro fine defects has been an extremely important subject in determination of an integrity of the circuit patterns or the wiring patterns in manufacturing of the circuit patterns or the wiring patterns.
However, the above-described micro structure has been further advanced and detection of micro fine defects of the patterns to be inspected such as the circuit patterns or the wiring patterns has reached the limit of resolution of the imaging optical system, and therefore essential improvement of the resolution has been demanded.
A prior art apparatus for essentially improving the resolution is disclosed in Japanese Patent Laid-Open No. Hei 5-160002. In this document, there is disclosed a pattern inspection apparatus which comprises an illumination arrangement for providing an annular-looped diffusion illumination formed with arrays of a plurality of virtual spot light sources for micro fine circuit patterns which is formed on a mask, through light source space filters, a light receiving arrangement having an optical pupil which sufficiently introduces a diffraction light from the micro fine pattern, which passes through or reflected from a mask which is almost uniformly diffusion-illuminated by the illumination arrangement and has imaging space filters for shutting off at least part of 0th order diffraction light or low order diffraction light of this introduced light, to obtain image signals by receiving the circuit pattern imaged through the optical pupil, and a comparison arrangement for comparing the image signals obtained by the light receiving arrangement with mask pattern data or wafer pattern data or data from a transfer simulator to inspect the pattern. In this document, there is also disclosed a method for controlling a shape of a light source space filter and an imaging space filter in accordance with the pattern shape data.
However, there has been a problem that, though, in the above-described prior art with respect to detection of a defect of the micro fine pattern. That is, although a defect of the micro fine pattern is detected by applying the annular-looped diffusion illumination to the micro fine pattern on the object to be inspected and sufficiently introducing the diffraction light from the micro fine pattern into the opening (pupil) of the objective lens to obtain high resolution image signals, full consideration has not been taken for the point that a micro fine defect should be detected with high reliability in response to various micro fine patterns existing on the object to be inspected.
Further, full consideration has also not been given for manufacturing semiconductor substrates having micro fine patterns such as a semiconductor wafer, a TFT liquid crystal substrate, a thin film multi-layer substrate and a printed board with reduced defects and high yield rate.
An object of the present invention is to solve the above problems of the prior art and to provide a method for manufacturing semiconductor substrates which is adapted to manufacture semiconductor substrates such as, for example, a semiconductor wafer, a TFT liquid crystal substrate, a thin film multi-layer substrate and a printed board, each having micro fine patterns, in a high yield rate.
Another object of the present invention is to provide a pattern detection method for detecting a pattern on an object to be inspected and an apparatus thereof (microscope system) which are adapted to detect a defect of a micro fine pattern with high reliability in response to various micro fine patterns provided on objects to be inspected such as a semiconductor wafer, a TFT liquid crystal substrate, a thin film multi-layer substrate, and a printed board.
A further another object of the present invention is to provide a method and an apparatus for inspecting a defect of a pattern on the object to be inspected which are adapted to inspect a micro fine defect of a micro fine pattern with high reliability in response to various micro fine patterns provided on objects to be inspected such as a semiconductor wafer, a TFT liquid crystal substrate, a thin film multi-layer substrate, and a printed board.
To achieve the above objects, a semiconductor substrate manufacturing method for manufacturing semiconductor substrates each having patterns formed by a manufacturing line comprising various process units, according to the present invention comprises: a history data or data base build-up step for building up history data or data base which shows a relation of causes and effects by accumulating in advance the history data or data base showing the relation of defect information of a pattern which appears on the semiconductor substrate and a cause of defect or a factor of defect which causes a defect of the pattern in the manufacturing line; a defect inspection step for detecting the defect information of the pattern by comparing image signals of the pattern on the semiconductor substrate with image signals of the reference pattern, for the semiconductor substrate which has reached a specified position of the manufacturing line; a defect analyzing step for analyzing a cause of defect or a factor of defect which causes a defect of the pattern in the manufacturing line located at an upper stream from the specified position of the manufacturing line, according to the defect information of the pattern detected in the defect inspection step and the history data or the data base which shows the relation of causes and effects, built up in the history data or data base build-up step; and a process condition control step for controlling process conditions in the above-described upper stream manufacturing line to eliminate the cause of defect or the factor of defect analyzed in the defect analyzing step.
With the configuration described above, the present invention enables inspection of micro fine defects with high resolution and high sensitivity on semiconductor substrates such as the semiconductor wafer, the TFT substrate, the thin film multi-layer substrate and the printed board each having micro fine patterns (for example, patterns the pitch of which is 1 xcexcm or under (0.8 to 0.4 xcexcm)), to reduce the number of micro fine defects on the semiconductor substrates by feeding back the results of inspection to the manufacturing processes for semiconductor substrates, and to manufacture the semiconductor substrates having micro fine patterns with a high yield rate.
According to the present invention, for materializing a manufacturing method of the semiconductor substrate, a method and apparatus for detecting a defect of the patterns on the object to be inspected are adapted to detect the pattern on the object to be inspected according to the image signals of the pattern on the object to be inspected which are obtained by concentrating an annular-looped diffusion illumination light formed by a plurality of virtual spot light sources and irradiating the illumination light onto the pattern on the object to be inspected through the pupil of the objective lens. The above configuration enables sufficient introduction of the reflected light which is obtained by slantly or obliquely introducing a focused illumination light from, for example, the annular-looped illumination onto a semiconductor substrate (object to be inspected), into the opening (pupil) of the objective lens and consequently obtain image signals of a pattern having a sufficient resolution, identify the reflected light by monitoring an image on the pupil plane of the objective lens, and detect the image signals of the pattern with the sufficient resolution and a large depth of the focus under an optimum condition at all times in response to a micro fine pattern by, for example, controlling the annular-looped illumination. By detecting a localization distribution or an intensity distribution of the reflected light from the image of the pupil plane (Fourier transformation plane) and controlling the annular-looped illumination in accordance with the localization distribution or the intensity distribution (corresponding to the density of pattern) of the detected diffraction light, the pattern can be sufficiently inspected with a normal resolution by the annular-looped illumination under the preset condition since the pattern density is not so high in a case of, for example, a 4 Mb DRAM memory device and the pattern can be inspected with the annular-looped illumination which provides a higher resolution under the preset condition in a case of, for example, a 16 Mb DRAM memory device. In addition, the pattern can be inspected with high resolution by using the annular-looped illumination under the preset condition since the pattern density is high at, for example, the cell part of the memory device and the pattern can be inspected at a high speed by using a normal illumination since the inspection sensitivity can be lowered in a rough area other than the cell part.
Furthermore, for implementing the above-described semiconductor substrate manufacturing method, a method and apparatus for inspecting a defect of a pattern on the object to be inspected according to the present invention are adapted to concentrate and irradiate the annular-looped diffusion illumination light comprising a number of virtual spot light sources onto the pattern on the object to be inspected through the pupil of the objective lens, compare an image signal obtained therefrom of the pattern on the inspected object with the image signal of the reference pattern, and erase the pattern on the inspected object when these image signals coincide and detect a defect when these image signals do not coincide.
The above-described configuration enables detection of high definition (high resolution) image signals from micro fine patterns and inspection of a defect on the micro fine pattern with high reliability since the high definition image signals can be compared with the high definition reference image signals with respect to a chip or cell.